Carton opening tool



Oct. 3, 1961 E. L. MERRITT- 3,002,273

CARTON OPENING TOOL Filed Sept. 12. 1960 INVENTOR.

Earl L. Merritt 3,002,273 CARTON OPENING TOOL Earl L. Merritt, 50 W.Summit Drive, Redwood City, Calif. Filed Sept. 12, 1960, Ser. No. 55,4059 Claims. (Cl. 30--2) This invention relates to a new and improvedcartonopening tool. More particularly the invention relates to a toolhaving a casing and a blade pivoted within the casing and moved by meansof a handgrip so that the cutting edge of the blade projects when thehandgrip is grasped by the fingers of the user.

A particular feature and advantage of the present invention is the factthat when pressure is applied to the handgrip the blade is therebyimmediately extended to cutting position and held in such position solong as finger pressure is applied to the grip. Thus, no special actionor adjustment is required to move the blade other than the normalgrasping of the fingers against the handgn'p.

A still further advantage of the invention is the fact that as soon aspressure on the handgrip is released, the blade is automaticallyretracted and held by spring action in retracted position. This featureof the invention is of particular importance in that it makes itimpossible unintentionally to leave the blade extended. Thus, when theuser is finished opening a carton he may safely put the tool in hispocket without danger.

Thus, a principal object of the present invention is to provide a toolof the character described wherein safety in use and storage is of primeconsideration.

Unintentional cutting of objects is eliminated and injury to the personof the user or a bystander is likewise eliminated.

A still further feature of the invention is the provision of means foradjusting the amount of projection of the blade. It will be understoodthat the thickness of cantons varies. At the same time it is highlyimportant that the cutting blade not project too far for fear that thecontents of the carton will be injured or the cutting blade injured. Thepresent invention provides a rapid, simple adjustment screw whichdetermines the extent of projection of the blade.

Still another feature of the invention is the simplicity of itsoperation and the facility with which cantons may be opened.

Other objects of the present invention will become apparent upon readingthe following specification and referring to the accompanying drawingsin which similar characters of reference represent corresponding partsin each of the several views.

In the drawings:

FIG. 1 is a vertical midsectional view showing the blade in retractedposition.

FIG. 2 is a view similar to FIG. 1 showing the blade in extendedposition.

FIG. 3 is a transverse sectional View taken substantially along the line3-3- of FIG. 1.

The tool which is the object of the present invention has a casing 11having a shape conveniently to fit inside the palm of the user. Thus,casing 11 has a back 12 curved to fit against the palm of the user andhaving a bump 13 at the front which extends upwardly into the spacebetween the thumb and fingers of the hand. The tool is thin, havingprojecting sides 14 extending downwardly beyond the back 12, there beinga space between the sides 14 to receive other parts of the tool. Thespace between the sides 14 is substantially straight and unobstructed.At the forward end of this space there is located a nose 16 of irregularshape held between the tates Patent ice sides 14 by a plurality ofscrews or rivets 17. Along one face of the nose 16 is an irregularlyshaped groove 18 to receive and permit pivotal movement of blade 19.Nose 16 has a slanted working edge 21 in which is formed a notch 22 forpurpose which hereinafter appears.

Blade 19 has a sharpened cutting edge 26 facing generally forwardly andbeing arcuate in shape. The blade 19 is pivoted by means of pivots 27 tonose 16, as well as to sides 14. An abutment 28 on the bottom of nose 16 limits projection of blade 19.

Mounted between sides 14 by means of transverse pivot 31 is handgrip 32which has its upper edge 33 received between sides 14 and has its bottomor finger engaging edge 34 extending below but generally parallel to thebottom edges of sides 14. A projection 36 at the end of edge 34 nearestpivot 31 and a similar projection 37 at the opposite end locates thetool within the fingers of the user. At its forwardend, grip 32 isrelieved as indicated by reference numeral 38 and at this portion is apivot 39 which extends into slot 41 in blade 19. Spring 42 is located ina recess 43 in the lower surface of back 12' and bears against the upperedge 33 of grip 32, thereby biasing the tool to the position as shown inFig. l with the blade 19 retracted. A counterbore 46 is formed in thetop surface of back 12 and receives the head of an adjustment screw 47threaded into back 12 and having its lower edge projecting into thespace between the sides 14. When the fingers of the user grip grip 32,adjustment screw 47 limits the upward pivotal movement of grip 32.Turning of screw 47 determines the amount of projection of blade 19.

In use, when the fingers are not gripping grip 32, spring 42 forces thegrip 32 downwardly and pivots the blade to the retracted position shownin FIG. 1. When the grip 32 is grasped by the fingers, it pivotsupwardly about pivot 31 to the position shown in FIG. 2, the adjustmentscrew 47 limiting the upward movement. Such move ment of grip 32 istransmitted by means of pin 39 and slot 41 to the blade 19 causing it topivot in a clockwise direction (as viewed in FIGS. 1 and 2) and itscutting edge 26 projects outwardly beyond the working edge 21 of nose16. This projected position is shown in FIG. 2. With the blade inextended position and by reason of the relationship of the groove 31relative to the pivot 27, the blade is held in extended position so thatpressure against the cutting edge 26 of blade 19 does not force theblade back into the casing. The tool is then drawn along the line atwhich the carton is to be cut, notch 22 facilitating the cuttingmovement. As soon as the user releases his grasp on the handgrip 32,spring 42 causes the blade to retract. Hence, the blade cannot injurethe person, clothing of the user or other objects by being leftunintentionally projected.

What is claimed is:

-1. A retractable blade tool comprising a handle formed with a hollow, ablade, means mounting said blade on handle for movement between aretracted position within said hollow and an extended position partiallyprojecting outside said handle, a finger grip movably mounted on saidhandle, and means articulately connecting said grip and blade whereby onmovement of said grip said blade is moved between retracted and extendedpositions.

2. A tool according to claim 1, which further comprises adjustment meansfor adjusting the amplitude of movement of said finger grip relative tosaid handle and thereby the maximum amplitude of projection of saidblade in extended position.

3. A tool according .to claim 2, which further comprises a spring insaid handle biasing said grip in a direction to retnact said blade.

4. A retractable blade tool comprising a handle formed with a downwardlyopening recess, a finger grip, means pivotally mounting said grip to afirst end of said handle partially within said recess, a blade, meanspivotally mounting said blade at the end of said handle opposite saidfirst end for movement between a retracted position within said recessand an extended position partially projecting outside said recess, andmeans connecting said grip and blade.

5. A tool according to claim 4, which further comprises a springinterposed between said handle and grip biasing said blade towardretracted position.

6. A tool according to claim 4, which further comprises an adjustmentscrew threaded into said handle and interposed in the path of movementof said grip adjnstably limiting the maximum amplitude of projection ofsaid blade.

7. A retractable blade tool comprising a handle formed with a downwardlyopening recess, a finger grip, means pivotally mounting said grip to afirst end of said handle partially within said recess, a nose fitting insaid recess 4 at the end of said handle opposite said first end, ablade, means pivotally mounting said blade on said nose for movementbetween a retracted position within the confines of said nose and anextended position partially projecting outside said recess, and meansarticulately conneoting said grip and blade whereby upon inward movementof said grip relative to said handle said blade is moved toward extendedposition.

8. A tool according to claim 7, in which the outer edge of said nose isslanted downwardly-inwardly toward said first end adjacent the point ofprojection of said blade to guide said blade and tool for cuttingmovement along the surface of a carton or the like.

9. A tool according to claim 8, in which said edge is formed with anotch adjacent said point of projection of said blade.

No references cited.

